The Core supports the Adult Children Study Program Project Grant (ACS PPG) by recruiting adult children of parents with and without dementia of the Alzheimer type (DAT) for comprehensive clinical and cognitive (psychometric) assessments at entry and every 3 years thereafter (annually for ACS participants >65y). The Core also supplies all Projects with participants. Core data are entered by Core personnel into the database maintained by the Data Management and Statistics (DMS) component of the Administration Core. The Clinical Core interacts directly or indirectly on a daily basis with virtually every facet of the ACS PPG. The Specific Aims of the Core are to: 1. Recruit, enroll, and maintain the ACS cohort to support the Projects in this application. In each of the first 3 years of the grant, the Core will enroll 80 ACS participants for a total sample of 240 participants. Participants will be recruited in 3 age groups in each of 2 categories: a. Category 1 (total sample = 120 participants): at least one biologic parent with DAT with age at onset (AAO) before 80y: 1) Age group 45-54y (n=40);2) Age group 55-64y (n=40);3) Age group 65-74y (n=40). b. Category 2 (total sample = 120 participants): neither biologic parent with DAT (both must be >70y): 1) Age group 45-54y (n=40);2) Age group 55-64y (n=40);3) Age group 65-74y (n=40). 2. Comprehensively assess the ACS participants with well-established clinical and cognitive measures every three years (annually for those >65y) and request voluntary permission for autopsy .3. Obtain blood for apolipoprotein E (apoE) genotyping and banking of extracted DNA and plasma (supported by the Genetics Core of the Alzheimer's Disease Research Center). 4. Coordinate the participation of ACS participants in all Projects: Project 1 - Amyloid imaging in the Adult Children Study;Project 2 - CSF markers of antecedent AD;Project 3 - Attentional profiles as an early marker of DAT;Project 4 - Neuroanatomical markers of early AD 5. Integrate all Core data with the DMS component of the Administration Core and interact cooperatively with all components of the PPG.